//
//  ========================================================================
//  Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd.
//  ------------------------------------------------------------------------
//  All rights reserved. This program and the accompanying materials
//  are made available under the terms of the Eclipse Public License v1.0
//  and Apache License v2.0 which accompanies this distribution.
//
//      The Eclipse Public License is available at
//      http://www.eclipse.org/legal/epl-v10.html
//
//      The Apache License v2.0 is available at
//      http://www.opensource.org/licenses/apache2.0.php
//
//  You may elect to redistribute this code under either of these licenses.
//  ========================================================================
//

package org.eclipse.jetty.server.ssl;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.security.cert.X509Certificate;

import javax.net.ssl.SSLPeerUnverifiedException;
import javax.net.ssl.SSLSession;
import javax.net.ssl.SSLSocket;

import org.eclipse.jetty.http.HttpSchemes;
import org.eclipse.jetty.io.EndPoint;
import org.eclipse.jetty.io.bio.SocketEndPoint;
import org.eclipse.jetty.server.Request;
import org.eclipse.jetty.util.TypeUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class SslCertificates
{
    private static final Logger LOG = LoggerFactory.getLogger(SslCertificates.class);

    /**
     * The name of the SSLSession attribute that will contain any cached information.
     */
    static final String CACHED_INFO_ATTR = CachedInfo.class.getName();

    public static X509Certificate[] getCertChain(SSLSession sslSession)
    {
        try
        {
            javax.security.cert.X509Certificate javaxCerts[]=sslSession.getPeerCertificateChain();
            if (javaxCerts==null||javaxCerts.length==0)
                return null;

            int length=javaxCerts.length;
            X509Certificate[] javaCerts=new X509Certificate[length];

            java.security.cert.CertificateFactory cf=java.security.cert.CertificateFactory.getInstance("X.509");
            for (int i=0; i<length; i++)
            {
                byte bytes[]=javaxCerts[i].getEncoded();
                ByteArrayInputStream stream=new ByteArrayInputStream(bytes);
                javaCerts[i]=(X509Certificate)cf.generateCertificate(stream);
            }

            return javaCerts;
        }
        catch (SSLPeerUnverifiedException pue)
        {
            return null;
        }
        catch (Exception e)
        {
            LOG.warn("EXCEPTION",e);
            return null;
        }
    }
    

    /* ------------------------------------------------------------ */
    /**
     * Allow the Listener a chance to customise the request. before the server
     * does its stuff. <br>
     * This allows the required attributes to be set for SSL requests. <br>
     * The requirements of the Servlet specs are:
     * <ul>
     * <li> an attribute named "javax.servlet.request.ssl_session_id" of type
     * String (since Servlet Spec 3.0).</li>
     * <li> an attribute named "javax.servlet.request.cipher_suite" of type
     * String.</li>
     * <li> an attribute named "javax.servlet.request.key_size" of type Integer.</li>
     * <li> an attribute named "javax.servlet.request.X509Certificate" of type
     * java.security.cert.X509Certificate[]. This is an array of objects of type
     * X509Certificate, the order of this array is defined as being in ascending
     * order of trust. The first certificate in the chain is the one set by the
     * client, the next is the one used to authenticate the first, and so on.
     * </li>
     * </ul>
     * 
     * @param endpoint
     *                The Socket the request arrived on. This should be a
     *                {@link SocketEndPoint} wrapping a {@link SSLSocket}.
     * @param request
     *                HttpRequest to be customised.
     */
    public static void customize(SSLSession sslSession, EndPoint endpoint, Request request) throws IOException
    {
        request.setScheme(HttpSchemes.HTTPS);

        try
        {
            String cipherSuite=sslSession.getCipherSuite();
            Integer keySize;
            X509Certificate[] certs;
            String idStr;

            CachedInfo cachedInfo=(CachedInfo)sslSession.getValue(CACHED_INFO_ATTR);
            if (cachedInfo!=null)
            {
                keySize=cachedInfo.getKeySize();
                certs=cachedInfo.getCerts();
                idStr=cachedInfo.getIdStr();
            }
            else
            {
                keySize=new Integer(ServletSSL.deduceKeyLength(cipherSuite));
                certs=SslCertificates.getCertChain(sslSession);
                byte[] bytes = sslSession.getId();
                idStr = TypeUtil.toHexString(bytes);
                cachedInfo=new CachedInfo(keySize,certs,idStr);
                sslSession.putValue(CACHED_INFO_ATTR,cachedInfo);
            }

            if (certs!=null)
                request.setAttribute("javax.servlet.request.X509Certificate",certs);

            request.setAttribute("javax.servlet.request.cipher_suite",cipherSuite);
            request.setAttribute("javax.servlet.request.key_size",keySize);
            request.setAttribute("javax.servlet.request.ssl_session_id", idStr);
        }
        catch (Exception e)
        {
            LOG.warn("EXCEPTION",e);
        }
    }

    /* ------------------------------------------------------------ */
    /* ------------------------------------------------------------ */
    /* ------------------------------------------------------------ */
    /**
     * Simple bundle of information that is cached in the SSLSession. Stores the
     * effective keySize and the client certificate chain.
     */
    private static class CachedInfo
    {
        private final X509Certificate[] _certs;
        private final Integer _keySize;
        private final String _idStr;

        CachedInfo(Integer keySize, X509Certificate[] certs,String idStr)
        {
            this._keySize=keySize;
            this._certs=certs;
            this._idStr=idStr;
        }

        X509Certificate[] getCerts()
        {
            return _certs;
        }

        Integer getKeySize()
        {
            return _keySize;
        }
        
        String getIdStr()
        {
            return _idStr;
        }
    }

}